Technical Field
The present invention relates to a rotor structure for a permanent magnet-type electric rotating machine.
Related Art
As a rotor structure for a permanent magnet-type electric rotating machine, Patent Literature 1 discloses a structure in which flux barriers (air gaps) are provided as a countermeasure against leakage magnetic flux at width-direction end portions of strip-shaped permanent magnets arranged to penetrate a rotor in an axial direction thereof.
Specifically, the strip-shaped permanent magnets are arranged at a regular pitch in a circumferential direction, while penetrating the rotor in the axial direction in a vicinity of an outer peripheral surface of the rotor. The flux barriers are provided at positions corresponding to the width-direction end portions of the permanent magnets in the rotor and extend to positions near the outer peripheral surface of the rotor. The flux barriers are provided to face the width-direction end portions of the permanent magnets.
By providing the flux barriers at the width-direction end portions of the permanent magnets, the width between the outer peripheral surface of the rotor and each flux barrier is reduced to reduce the leakage magnetic flux (magnetic flux which is not linked to the stator and does not contribute to the torque), and the motor torque is improved by increasing the magnetic flux of the magnets usable as the motor torque.